Essential hypertension is a critical problem for older adults. There are 60 million or more Americans with hypertension, many of whom are aged. Hypertension is a particular problem among African American who are at much higher risk of hypertension that Caucasians. Grave consequences of uncontrolled primary hypertension include strokes, heart disease, and end stage renal disease. What is particularly tragic about hypertension is that extremely effective oral medication treatments for hypertension are readily available. Thus, a primary issue to control hypertension is ensuring that prescription medication is taken after it is dispensed. In the proposed research, a cognitive model for understanding medication adherence is applied to a sample of low- SEA African-American and Caucasian subjects who are middle aged to very old. Novel electronic devices to monitor adherence are used to provide accurate measures of medication-taking behavior. It is hypothesized that psychosocial variables, such as illness representation and depression, play a substantial role in medication adherence for younger adults, and these variables will be assessed. In older adults, however, there is growing evidence that age-related decline in cognitive function may play an important role in medication adherence, particularly for the oldest-old. In addition to assessing the magnitude of the adherence problem for hypertensive medications as well as other medications, the proposed research examines the effectiveness of different types of interventions--interventions designed to either alter an illness representation or support cognition. The interventions examined include providing patients with organizational charts and medication organizers to reduce comprehension and working memory load associated with the adherence burden, providing patients with external reminder devices to support prospective memory, or providing patient counseling to restructure the patient's illness presentation to be more consonant with a desire to adhere. The ultimate outcome of this project will be to develop profiles of individuals who are at high risk of nonadherence and provide practitioners with specific intervention strategies that are inexpensive and have been demonstrated to be effective in improving adherence.